Bulb guide on molding diaphragm



y 20, 1958 J. c. WHITESELL 2,835,004

BULB GUIDE 0N MOLDING DIAPHRAGM Filed Aug. 29, 1955 ,fr'zvez far. 62 CT Mia 665% United States Patent 2,835,004 BULB GUIDE ON MOLDING DIAPHRAGM John .C. Whitesell, Chicago, Ill., assignor to Crane Co.,

Chicago, 111., a corporation of Illinois Application August29, 1-955, Serial No. 53'1,203

14 Claims. -.(CI. 22-68) apparatus-by which a recess 1nay=beformed in the mold,

as,for example, to serve as an enlargement or reservoir at the mouth of the sprue "or riser, substantially exactly at a predetermined'loeation. To this end, a bulb or projection is formed on the diaphragm to. press into the mold material as "thediaphragm is expanded and thus form a reservoir or recess, andguide means are provided to assure that the bulb moves into the desired position.

-lt'is accordingly an object of the present invention to provide, inlmold forming apparatus employing akpressure diaphragm means for .forming a recess in'the mold at a predetermined'location.

It is another object of the invention to provide a reset voir-forming 'bulb on an .expansible pressure-applying diaphragm of mold-forming apparatus and means .for controlling the location of the'bulb relative "to passage- ;forming means in the mold.

Another object is the provision, in mold-forming apparatus of the typeemploying a diaphragm to aPPlypressure to moldable material, ofjguide meansforaccurately locating'a projection provided onthe .diaphragm'toform arecess'i'n'the mold material in a desired'pos'ition.

A "further object is the provision oi'r-a diaphragm construction presenting abulb or projection on one face of a diaphragm and aguide .rod fixedrel'ativetoithe bulb and extending oppositely relative thereto.

'l he above and other objects,'advantages, andfeatures of thei'nvention willbe'apparent'fromthe followin'g detailed "description, taken in co-njunc tion'with the accompanyin'g *drawingfin which:

The single figure is a vertical sectional view through 'mold forrninjg apparatus. incorporating one embodiment of'theinvention. v i I Referring 'tothedrawing, thereis shown'a mold 'box :10, comprisingpart or ajfiaSk, such'as a co'pe or "drag, disposed on a patternplate 11 on which a desiredpattern 121s mounted. Aspruefform 113 extends "from adjacent the pattern'into the mold material 14, which in this case 'is shown as the usual moldingsandu- 'lhe form 513 is tubular and removably positioned a't .any appropriate .point relative, tmthepattern. A form totPlfovide a-riser in the. mold may .also :be employed, but in the ;present case a riser is dispensed with.

:"Means 1 for compressing r the sand: or Lothertmoldingmaaterial 1 4 iaregrnrovi'de'd in therform ofza pressureihead whieh comprises a i easing-.115 peripherally iconformin g to 2,835,004 Patented May 20, 1958 into which fluid under pressure may be admittedthrough a conduit 20 under control of valve 21. .When fluid under pressure enters the chamber, the diaphragm I7 .pass'es upon the mold material 14 to compact the same about the pattern. Upon release of thepressure, the diaphragm returns to its normal substantially fiat position. Suction means may be employed for retracting the diaphragm if desired. Any suitable means (not shown) may be utilized'to holdthe ring member and the top of the mold box tightly engaged during the application of the mold formingpressure.

In order to form a reservoir at the mouth-of the sprue in the completed mold, a projection or bulb.22 of -the desired shape is formed on the diaphragm extending exteriorly of thepressure chamber 19. The bulb is of substant'ially rigid construction, so that it may penetrate 'the -mold material without difficulty. In theillustrated embodiment, the bulb is generally frusto-conical and comprises a solid metallic body or filler 23 havingbonded to its outer surface a covering2'4 of material similar to that of the diaphragm 17. An aperture is formed in the diaphragm through which the bulb projects, the covering 24 or the bulb being vulcanized or otherwise suitably secured to the diaphragm adjacent the aperture. Thebulb 22 isso located on the diaphragm as to align withthe sprue form 13. .Aguide rod 25 or similar rigidmember .extending interiorly of the pressure chamber 19 'is fixed to the bulb for movement therewith, as 'by the threaded connection shown rigidly securing the rod Lto the bulb or by apivotal or like connection permitting relative swinging of the lbulb and rod. "Means of any suitable type are provided in the chambertor receiving and guiding the rod, in the present instance taking the format atube 26 opening from the closure 16.and extending outwardly from the pressure chamberand thus forming a part thereof. The outer end ofthe tube is sealingly closed'by a cap 27 so as to prevent escape of the pressure fluid from the chamber 19. The guidetube 26 is disposed substantially in alignment with the sprue form 13, and is so dimensioned relative tofthe rod25.as to receivevthe'latter for guided reciprocal movement therein substantially in alignment with the sprue form. A certain amount of lateral movement of the rod is preferably provided for, however, as exaggeratedly shown in the drawing. The rod and tubeinthe disclosedembodiment are straight, butit is'to be understood that if desired they may be curved so as to correspond to acurved path which the .bulb is to follow in moving with the diaphragm.

It will be evident'that when the diaphragm is.expanded to compact the mold materiaL'thebulb 22 is moved'therewith .until it comes intocontact with the end of the sprue form'by whichits movement is halted, the guide.means assuring that the bulb does not come to a position out of alignment with the sprue form. The bulb in its'movement toward the sprue form displaces the sandor other mold material 14 out of'its path, some of which-is 'displaced downwardly "through the form, so thatno such material lies between the bulb and the mouth of the form. 'Thusflthe sprue form and bulb together provide in-the completedmold asprue with an enlarged'reservoir at its mouth-in full communication therewith.

Upon completion of the pressure applying operation,

A diaphragml7 of rubber-or likeemasealed relation to said head the diaphragm is retracted either by its own elasticity or by suction, as previously described, or in any other suitable manner. Obviously, the bulb may be employed to form a recess in the mold for other purposes than to provide a reservoir in communication with the sprue, and

' in such case the construction described assures that such recess will be properly located in every instance. if desired, suitable stop means may be provided to limit the movement of the rod 25, as to locate the bulb when it is not stopped by a form or other member disposed in the mold, or to prevent the possibility of excessive pressure of the bulb against the sprue form.

I claim:

1. In apparatus for making molds, a pressure head, an expansible pressure-applying diaphragm secured in and defining therewith a fluid-tight chamber, a substantially straight guide tube extending exteriorly of said chamber from the head closed at its outer end, a guide rod extending in the chamber reciprocably received .tially rigid bulb formed on the diaphragm exteriorly in said tube, a substanof the chamber in substantial alignment with said tube, and means fixing said rod to the bulb.

2. In apparatus for making molds, a pressure head, an expansible pressure-applying diaphragm defining a fluid-tight chamber with said head, a closed tubular projection on said head extending outwardly of said chamber and open to the chamber at its inner end, a substantially rigid bulb on said diaphragm exteriorly of the chamber, and a guide rod fixed to said bulb extending interiorly of the chamber reciprocably guided in said tubular projection.

3. In apparatus for forming molds, a pressure head, an expansible pressure-applying diaphragm defining a fluid-tight chamber with said head, a substantially straight tubular formation on said head open to the chamber at its inner end and closed at its outer end, a rod extending interiorly of the chamber reciprocably guided in said tubular formation, a substantially rigid projection on.

the diaphragm exteriorly of the chamber in substantial alignment with said tubular formation, and means fixing the projection to said rod.

4. In apparatus for making molds, a pressure head, an expansible pressure-applying diaphragm defining a fluid-tight chamber with said head, a substantially rigid projection on the diaphragm exteriorly of the chamber, a guide member extending interiorly of the chamber from said projection, and guide means on said head having an axis in substantial alignment with said projection receiving said member for reciprocating movement.

5. In apparatus for forming molds, a pressure head, an expansible pressure-applying diaphragm defining a fiuid-tight chamber with said head, guide means fixed in said chamber having an axis passing through the chamber, a projection on the diaphragm exteriorly of the chamber substantially in alignment with said axis, and a member extending interiorly of the chamber secured to said projection and reciproeable in said guide means.

6. In apparatus for making molds, a pressure head, an expansible pressure-applying diaphragm defining a fluid-tight chamber with said head, fixed guide means in the chamber, means reciprocally guided in said guide means, and a bulb on said diaphragm exteriorly of the chamber fixed to said guided means, and movable by the diaphragm in a path determined by the aforesaid means.

7. In apparatus for making molds, a pressure head, an expansible pressure-applying diaphragm defining a fluid-tight chamber with said head, a bulb on said diaphragm exteriorly of the chamber and movable therewith, and means guiding movement of the bulb including guide means fixed in the chamber and means secured to the bulb for movement therewith guidedly engaging with said guide means.

8. In a mold-forming apparatus substantially as described, the combination of a mold box 'for containing moldable material and removable means forming a passage in said material, compression means comprising a pressure head and an expansible diaphragm defining therewith a fluid-tight chamber and engaging in pressing relation on said material, a tubular guide on said head substantially aligned with said passage-forming means and open to the chamber, a substantially rigid bulb on the diaphragm exteriorly of the chamber substantially in alignment with said passage-forming means and engaging therewith in reservoir-forming relation upon expansion of the diaphragm, and a guide rod fixed to said bulb extending interiorly of the chamber engaging in said tubular guide for substantially rectilinear movement.

9. In a mold-forming apparatus substantially as described, a mold box for containing moldable material and removable means forming a passage in said material, compression means comprising a pressure head and an expansible diaphragm defining therewith a'fluid-tight chamber and exerting compressional forces on the moldable material, a substantially rigid projection on said diaphragm exteriorly of said chamber substantially aligned with said passage-forming means and engaging therewith upon expansion of the diaphragm to form a reservoir in the ma terial, a guide member extending interiorly of the chamber secured to said projection, and a substantially straight tubular formation on said head guidingly receiving said member for substantially rectilinear reciprocation thereof.

10. In a mold-forming apparatus substantially as described, a mold box for containing moldable material and means defining a passage in said material, compression means engaging said mold box comprising a pressure head and an expansible diaphragm defining therewith a fluidtight chamber and exerting compressional forces on said moldable material, a projection on said diphragm exteriorly of said chamber engaging said passage-defining means to form a reservoir upon expansion of the diaphragm, a guide member extending interiorly of the chamber from said projection, and guide means fixed in the chamber reciprocably receiving said member and controlling therewith movement of the projection into engagement with said passage-forming means.

11. In a mold-forming apparatus substantially as described, a mold box for containing moldable material, compression means engaging said mold box including a pressure head and a diaphragm defining therewith a fluidtight expansible chamber and exerting compressional forces on said moldable material, a projection on said diaphragm exteriorly of said chamber forming a recess in said material, a guide member extending interiorly of the chamber from said projection, and means fixed in the chamber guidingly receiving said member for substantially rectilinear reciprocation thereof.

12. In a mold-forming apparatus substantially as described, a mold box containing moldable material, compression means comprising a pressure head and an expansible diaphragm defining therewith a fluid-tight chamber and exerting compressional forces on said moldable material, a projection on the diaphragm exteriorly of the chamber movable by the diaphragm forming a depression in said material, a guide member secured to said projection extending interiorly of the chamber, and guide means fixed in the chamber guidingly receiving said member for reciprocable movement determining the path of said projection.

13. As an article of manufacture, a diaphragm construction comprising a sheet of elastic material, a substantially rigid bulb formed on said sheet and projecting from one face thereof, and a guide member fixed to the bulb projecting from the opposite face.

14. A diaphragm construction for use in mold-forming apparatus of the type described, comprising an expansible web having a substantially rigid bulb thereon and project- 5 ing from one face thereof and a guide member fixed to 1,846,279 said bulb extending from the opposite face. 2,275,806 2,698,976 1 References Cited in the file of this patent UNITED STATES PATENTS 239,567 $69,691 Van Tine Oct. 20, 1896 569,093

6 Speirs Feb. 23, 1932 Perazo Mar. 10, 1942 Taccone Jan. 11, 1955 FOREIGN PATENTS Germany Oct. 16, 1911 Great Britain May 3, 1945 

